JP5887281B2 - Multi-beam X-ray system - Google Patents

Description

  A typical x-ray analysis instrument includes an x-ray source and an x-ray optical system that provides an x-ray probe beam. The characteristics of the probe beam determine the characteristics and capabilities of the instrument. Probe beam performance parameters include divergence for spatial definition, bandwidth for energy definition, and intensity for a given cross-section. These parameters, however, cannot be optimized independently because improving one parameter often reduces the performance of the other parameters. Many x-ray probe beams use characteristic emission lines that result from interactions between target atoms and accelerated electrons. The spectrum that the optical system can deliver is limited by the available spectrum from the particular target.

  Current technology in x-ray sources and x-ray optics is unable to deliver an ideal probe beam with attributes of absolute parallelism, very narrow energy bandwidth, variable wavelength, and very high intensity. Instead, different optical systems are constructed and arranged to deliver beams with different characteristics. In combination with different x-ray source designs, the optical system delivers the beams required for different instrument capabilities, functions and applications. This approach typically involves multiple optical systems and multiple x-ray tubes or even multiple targets and is therefore inconvenient and costly to manage.

  Some systems employ multilayer optics that include a bending mechanism that changes the curvature of the multilayer optics for different wavelengths. While such systems allow the use of different sources, mechanical systems that can reliably and accurately form curvatures that match specific wavelengths are difficult to produce. In addition, multilayer optics designed to operate at multiple wavelengths cannot be optimized for each particular wavelength.

  These multilayer optics systems may also include multiple sections of optics where each section is designed for a specific wavelength. The section of the optical system is mechanically moved to the operating position when a specific operating wavelength is required. However, these systems do not address the problems associated with the two-dimensional case.

  Such multilayer optical system further includes a plurality of multilayer coating arrangements as a stack of structures where each structure is designed for a specific wavelength. These systems offer convenience and low cost, but their performance is compromised due to lower reflectivity for all specific wavelengths and high background noise due to Bragg reflection at different energies from different multilayer coating structures. It has been done.

  Other systems have been employed as two-dimensional systems that include two two-dimensional optical systems in a face-to-face arrangement. Each optical system is designed for a different energy or wavelength. However, such an arrangement has one or both optics at a source take-off angle far away from the ideal take-off that is optimal for performance.

  Even with optical systems designed for the same energy, it may be necessary to quickly change the configuration among various beam configurations, such as parallel beam and focusing beam configurations.

  Therefore, there is a need for a probe beam system that can deliver beams of different characteristics.

  In one form, a multi-beam x-ray optical system includes an x-ray source that emits x-rays and a housing having a first portion and a second portion. The second part is movable relative to the first part and includes a plurality of optical systems with different performance characteristics. Each optical system is placed in an operating position through movement of the second part relative to the first part so that the optical system receives X-rays from the X-ray source and directs the X-rays to the desired position.

  The benefits of X-ray optical systems include improved functionality, improved performance, enabled equipment capabilities, convenience and low cost.

  Additional features and advantages of the invention will be readily apparent to those skilled in the art after reviewing the following description with reference to the drawings and the appended claims forming a part of this specification. Let's go.

  The accompanying drawings, which are incorporated in and form a part of the specification, depict some aspects of the invention and, together with the description, serve to explain the principles of the invention. The components in the figures are not necessarily full scale, but instead emphasis is placed on depicting the principles of the invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the drawings.

FIG. 1A is an exploded perspective view of a multi-beam X-ray system according to the invention. FIG. 1B is a cutaway view of the multi-beam X-ray system of FIG. 1A. FIG. 2A is a schematic diagram depicting the principle of the multi-beam X-ray system of FIG. 1A. FIG. 2B is a schematic diagram depicting the principles of the multi-beam X-ray system of FIG. 1A. FIG. 3A is a schematic diagram depicting the principles of another embodiment of a multi-beam X-ray system. FIG. 3B is a schematic diagram depicting the principles of another embodiment of a multi-beam X-ray system.

  An x-ray optical system capable of delivering beams with different properties is described herein. The optical system includes a plurality of optical systems, each optical system having unique performance characteristics to meet the needs of different applications. Beam characteristics are spatially defined variations such as parallel beam optics and focusing optics, spectral differences such as CuKα, MoKα, AgKα and other wavelengths, different tradeoffs between divergence, flux on the sample, Alternatively, all of the above may be included. The optical system delivers a particular beam when the corresponding optical system is mechanically placed in the desired optical path.

  Referring now to FIGS. 1A and 1B, a multi-beam x-ray system embodying the principles of the present invention is depicted therein and indicated at 10. As its primary component, the x-ray system 10 includes an optical system 12 enclosed within a housing 14 and a cover 16.

  The multi-beam x-ray system 10 employs a mechanism for placing a particular optical system in a desired operating position, where each optical system is within certain constraints, its optimized take-off angle, and design. Defined working source position, matched source focal spot and optics focal point, and working position with correct Bragg angle. The constraints may include the designed interception points for all beams, the intended beam orientation and position, and any other desirable constraints. In the arrangement shown in FIGS. 2A and 2B, the optical system 12 includes a rotating mechanism for placing the optical element 18 with a pair of optical systems 20 and 22 in a desired operating position, where the optical systems 20 and 22 are present. Are arranged in a circular geometry, and the optical system 12 is rotated about its axis so that each optical system 20 and 22 is placed in and out of the operating position.

  The optical element 18 is such that the optical system 20 or 22 is roughly aligned with the intended source focal spot 26 or 28 of the source 24 in the system 10 when the system 10 is positioned for the optical system in its operating position. There may be a coarse alignment mechanism for each optical system 20 and 22 so that the optical systems are aligned in a manner. Alternatively or additionally, optical system 12 and optical systems 20 and 22 are rough to the source focal spot where the optical system is intended when optical system 12 is positioned for the desired optical system in its operating position. It is made so that it is aligned in advance with the accuracy and precision of the alignment.

  In use, the source 24 emits x-rays from either the source focal spot 26 or 28 in the respective optical system 22, 20, while the beam is focused on the focus 30, detector, sample, or any other suitable Focus on position. In particular, in the arrangement shown in FIGS. 2A and 2B, a housing 14 called a rotary housing has a structure with two shells 15 and 17 (FIG. 1B). The inner shell 15 provides a plurality of positions for the optical systems 20, 22 having different characteristics. The inner shell 15 is the axis of the optical instrument 12 as indicated by the arrow 19 relative to the outer shell 17 so that either of the optical systems 20, 22 can be placed in a predefined operating position. Can be rotated in either direction around. As indicated above, each optical system 20, 22 is pre-aligned or coarsely aligned with the respective source focal spot 28, 26 in the intended direction or position when it is moved to the activated position. . Each optical system 20, 22 may have its own coarse alignment mechanism, or it can be installed in the optical system 12 at the factory with the accuracy of the coarse alignment mechanism. The static outer shell can include lateral translation across the main beam direction, Bragg angle alignment, and optional alignment motion required for micro-alignment along the main beam. It may be equipped with an alignment mechanism that provides everything.

  Alternatively, the alignment required for the micro-alignment where the optical system 12 may include lateral translation across the main beam direction, Bragg angle alignment, and optional translation along the main beam. Can be equipped with an alignment mechanism that provides all of the movement.

  Another arrangement shown in FIGS. 3A and 3B is shown by an arrow 132 with an optical element 18 having a pair of optical systems 120 and 122, all enclosed in a housing similar to the housing 14 (FIG. 1A). 1 depicts an optical system 112 with a translation mechanism for positioning back and forth to the desired operating position relative to the outer shell 117. The optical systems 120 and 122 are arranged in a linear array, or a two-dimensional matrix if more optical systems are included in the system, and the particular optical system is translated to the operating position. Similarly, the source 24 emits X-rays from either the source focal spot 26 or 28 in the respective optical system 122, 120, while the beam is focused on the focus 30, detector, sample, or any other suitable Focus on position.

  The optical systems 120, 122 have different properties such as different spatial definitions or different energies. For different energy cases, the optical systems 120, 122 can be employed for different spectra and can be aligned to different source focal spots. Each optical system 120, 122 may be pre-aligned or coarsely aligned with the respective source focal spot 28, 26 in the intended direction or position when the optical system is placed in its desired operating position. Each optical system 120, 122 may have its own coarse alignment mechanism, or it may be installed at the factory with a defined coarse alignment mechanism accuracy. The housing 117 provides all of the desired alignment degrees of freedom for fine alignment, which may include lateral translation across the main beam direction, Bragg angle alignment, and optional translation along the main beam. Can be equipped with a mechanism.

  Alternatively, the optical system 112 may include a lateral translation across the main beam direction, a Bragg angle alignment, and an optional translation along the main beam, with the desired alignment degrees of freedom for fine alignment. It can be equipped with its own alignment structure that provides everything.

  The optical arrangement described above can be employed with different target materials to form two or more source focal spots with different radiation characteristics. Each optical system is aligned with a specific focal spot on a specific target material. Beams with different wavelengths are delivered by operating different target focal spots and using slits to select the beams.

  The optical system may be designed to provide a beam with the same energy but different spatial characteristics, such as a collimated beam and a focus beam. The arrangement in this case uses the same target material and the same source spot.

  The optical system can deliver multiple beams with mixed characteristics such that some beams have different energies and some have only different spatial definitions. In this case, multiple target materials and source radiation spots can be employed, and multiple optical systems can be aligned to a single source spot.

  In any of the previously described arrangements, the x-ray source 24 is a point source with a single target material or multiple target materials. An x-ray source with multiple target materials (both sealed tube and rotating anode) can include targets with multiple strips, each strip being a different target material. Source focal spots associated with different target materials can have different positions. Thus, X-ray optics can be designed for different target materials with different focal spots on the target. Alternatively, the target can be a mixture of different elements that emit a spectrum that includes all of the characteristic lines from all elements. The optical system can have the same focal spot regardless of the operating wavelength.

  When the X-ray source 24 is used with a different target material having a strip structure, the source 24 has a cathode so that the different target material can be placed at the desired focal spot where the electron beam interacts with the target. The target may be mechanically movable. The electron beam can be manipulated electronically to different target materials so that different spectra can be generated at different focal spots.

  In a particular arrangement, the x-ray source 24 provides point projection and the system 10 includes a rotating housing with a plurality of two-dimensional optics as shown in FIGS. 2A and 2B. X-ray sources have a single target and deliver different characteristic emission lines such as Kα and Kβ. The optics are different, such as parallel beams, focusing beams with different focal lengths, and beams with different spectral definitions such as different operating wavelengths (Kα, Kβ, Lα,...) And different bandwidths. A beam with a spatial definition can be delivered. Each optical system can be rotated to an operating position to deliver the designed beam characteristics.

  In another arrangement, the x-ray source 24 delivers a radiation spectrum from one or more target materials, such as CrKα / Kβ, CuKα / Kβ, MoKα / Kβ, and others, and the system 10 includes a plurality of two-dimensional Includes a rotatable housing with optics. Each optical system is employed for a specific wavelength and / or has a specific set of properties. X-rays of a single target or different targets can be from the same source spot if it is a single target material or made from a mixture of targets, or from a strap of material with different source targets If so, it can be emitted from different source points. Each optical system is configured and coarsely aligned so that its focal point is aligned with the intended source focal spot and delivers the beam according to the designed direction and position. The rotating mechanism can place any optical system in the circular structure in the operating position. The micro-alignment structure engages the optical system in the operating position so that the optical system is micro-aligned for optimal performance.

  In yet another arrangement, the x-ray source 24 delivers a radiation spectrum from one or more target materials such as CrKα, CuKα / Kβ, MoKα / Kβ, and others, and the optical system 10 includes a linear array or a plurality of A matrix housing with a two-dimensional optical system (see, eg, FIGS. 3A and 3B). Each optical system is configured for a specific wavelength and / or has a specific set of properties. X-rays from a single target or different targets are emitted from the same source spot, or multiple source points, if it is a single target or made from a mixture of targets be able to. Each optical system is configured and coarsely aligned so that its focus is aligned with the intended source focal spot and delivers the beam according to the desired direction and position. The translation mechanism places either the array or the optical system in the matrix in the operating position. The micro-alignment structure engages the optical system in the operating position so that the optical system is micro-aligned for optimal performance.

  X-ray source 24 may include an anode with a different material and a cathode that delivers an electron beam to different materials to form different source focal spots that emit different spectra. The cathode can be an electron gun with an electromagnetic deflection mechanism for manipulating the electron beam to different target materials. Alternatively, the anode can be repositionable so that different materials can be placed under the electron beam to produce x-rays with different spectra.

  The optical system can be a multilayer optical system. The multilayer optical system is a stepped multilayer optical system, and can be any combination of a collimating optical system and a focusing optical system having different focal lengths.

  In some implementations, each two-dimensional optical system is described in US Pat. Nos. 6,042,099 and 6,014,423, which are hereby incorporated by reference in their entirety, either sequentially as in the Kirkpatrick-Baez scheme. Made from two one-dimensional optical systems in either of the “side-by-side” arrangements. The two-dimensional optical system can be a single reflection optical system having a parabolic geometry for collimating optics or an ellipsoidal geometry for focusing optics. .

  The foregoing and other embodiments are within the scope of the following claims.

Claims (14)

An X-ray source having a different spectrum ;
A housing having a first part and a second part, wherein the second part is movable relative to the static first part, the second part being perpendicular to the axis of the X-ray beam Each optical system includes a plurality of two-dimensional multilayer X-ray optics that condition the beam in two directions, such that the optics receives X-rays from an X-ray source and directs X-rays with different performance characteristics to a desired location. A multi-beam x-ray beam system comprising: a system disposed in an operative position through movement of a second portion relative to the first portion. Each optical system assortment Erareru so when the optical system is arranged in its active position includes a second portion there line placement mechanism, the optical system, the source focal spot desirable with the intended beam direction and beam position two assortment gills are and, a line instrument mechanism, at least some of the X-rays align each optical system as will be reflected through an optical system, multi-beam X-ray beam system of claim 1. Optics, are gills two assortment desirable source focal spot with the intended beam direction and beam position, so that at least some of the X-rays are reflected through an optical system, the optical system is aligned in advance, wherein The multi-beam X-ray beam system according to Item 1. The first portion comprises an alignment mechanism for obtaining Assortment each optical system when the optical system is arranged in its working position, the optical system, the source focal spot two assortment example desirable with the intended beam direction and beam position The multi-beam x-ray beam system of claim 1. The second portion comprises an alignment mechanism for obtaining Assortment each optical system when the optical system is arranged in its working position, the optical system, the source focal spot two assortment example desirable with the intended beam direction and beam position The multi-beam x-ray beam system of claim 1.   The optical system housing is a rotary housing having an outer shell and an inner shell, the inner shell is the second part and the outer shell is the first part, and the plurality of optical systems in the inner shell are circular. The multi of claim 1, wherein each optical system is positioned in its desired operating position by rotating the inner shell relative to the outer shell. Beam X-ray beam system.   The optical housing is a housing having a first portion of an outer shell and a second portion having a linear array or matrix structure and having a plurality of optical systems movable relative to the outer shell. The multi-beam x-ray beam system of claim 1, wherein each optical system is placed in its operative position by translating the second portion relative to the outer shell.   The X-ray source includes an anode with a different target material and a cathode that delivers an electron beam to different materials to form different source focal spots that emit different spectra, from which the X-rays are emitted. The multi-beam x-ray beam system of claim 1, wherein the spot is a spot on the emitted x-ray source.   9. The multi-beam x-ray beam system of claim 8, wherein the cathode is an electron gun with an electromagnetic deflection mechanism for manipulating the electron beam to different target materials.   The multi-beam source of claim 1, wherein the x-ray source includes an anode that can be repositioned with different target materials such that different materials are placed under the electron beam to produce x-rays with different spectra. Beam X-ray beam system.   The multi-beam X-ray beam system according to claim 1, wherein the two-dimensional multilayer X-ray optical system is a multi-layer optical system having a graded d interval.   12. The stepped multilayer optical system is any combination of collimating and focusing optics with different combinations of performance attributes including divergence, focal length, operating energy, and energy bandwidth. Multi-beam X-ray beam system.   12. The multi-beam of claim 11, wherein each of the two-dimensional multilayer optics is made from two one-dimensional optics in either a side-by-side geometry or a sequential Kirkpatrick-Baez geometry. X-ray beam system.   12. The multi-beam X-ray of claim 11, wherein the two-dimensional optical system has a parabolic geometry for collimating the X-ray beam or an ellipsoidal geometry for focusing the X-ray beam. Beam system.

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